import sys
import random
import pygame
from pygame.locals import *

class MySprite(pygame.sprite.Sprite):
    def __init__(self, target):
        pygame.sprite.Sprite.__init__(self)
        self.master_image = None
        self.frame = 0
        self.old_frame = -1
        self.frame_width = 1
        self.frame_height = 1
        self.first_frame = 0
        self.last_frame = 0
        self.colums = 1
        self.last_time = 0

    #X property
    def _getx(self):
        return self.rect.x
    def _setx(self, value):
        self.rect.x = value
    X = property(_getx, _setx)

    #Y property
    def _gety(self):
        return self.rect.y
    def _sety(self, value):
        self.rect.y = value
    Y = property(_gety, _sety)

    #position property
    def _getpos(self):
        return self.rect.topleft
    def _setpos(self, pos):
        self.rect.topleft = pos
    position = property(_getpos, _setpos)

    def load(self, filename, width, height, colums):
        self.master_image = pygame.image.load(filename).convert_alpha()
        self.frame_width = width
        self.frame_height = height
        self.rect = Rect(0, 0, width, height)
        self.colums = colums
        #try to auto-calcuate total frames
        rect = self.master_image.get_rect()
        self.last_frame = (rect.width//width)*(rect.height//height) - 1

    def update(self, current_time, rate=30):
        #update animation frame number
        #print(current_time)
        if current_time > self.last_time + rate:
            self.frame += 1
            if self.frame > self.last_frame:
                self.frame = self.first_frame
            self.last_time = current_time
        #build current frame only if it changed
        if self.frame != self.old_frame:
            frame_x = (self.frame % self.colums)*self.frame_width
            frame_y = (self.frame // self.colums)*self.frame_height
            rect = Rect(frame_x, frame_y, self.frame_width, self.frame_height)
            self.image = self.master_image.subsurface(rect)
            self.old_frame = self.frame

    def __str__(self):
        return str(self.frame) + "," + str(self.first_frame) +\
                "," + str(self.last_frame) + "," + str(self.frame_width) +\
                "," + str(self.frame_height)



def print_text(font, x, y, text, color=(255,255,255)):
    img_text = font.render(text, True, color)
    screen.blit(img_text, (x,y))

def reset_arrow():
    y = random.randint(250,350)
    arrow.position = 800,y

# main program begins
pygame.init()
pygame.display.set_caption("Escape the Dragon Game")
screen = pygame.display.set_mode((800,600))
font = pygame.font.Font(None, 18)
framerate = pygame.time.Clock()

#load bitmap
bg = pygame.image.load("background.png").convert_alpha()

#create the dragon sprite
group = pygame.sprite.Group()

#create the dragon sprite
dragon = MySprite(screen)
dragon.load("dragon.png", 260, 150, 3)
dragon.position = 100,230
group.add(dragon)

#create the player sprite
player = MySprite(screen)
player.load("caveman.png", 50, 64, 8)
player.first_frame = 1
player.last_frame = 7
player.position = 400,303
group.add(player)

#create the arrow sprite
arrow = MySprite(screen)
arrow.load("flame.png", 40, 16, 1)
arrow.position = 800,320
group.add(arrow)

arrow_vel = 8.0
game_over = False
you_win = False
player_jumping = False
jump_vel = 0.0
jump_before = 0.0
player_start_y = player.Y
score = 0

# main loop
while True:
    framerate.tick(30)
    ticks = pygame.time.get_ticks()

    for event in pygame.event.get():
        if event.type == QUIT:
            sys.exit()
        elif event.type == KEYUP:
            if event.key == pygame.K_SPACE:
                if not player_jumping:
                    player_jumping = True
                    jump_vel = -8.0 + jump_before
                    if jump_vel < -16:
                        jump_vel = -16
    keys = pygame.key.get_pressed()
    if keys[K_ESCAPE]:
        sys.exit()
    elif keys[K_SPACE]:    # space for jumping
        if not player_jumping:
            jump_before -= 0.5


    #update the arrow
    if not game_over:
        arrow.X -= arrow_vel
        if arrow.X < -40:
            reset_arrow()

    #did arrow hit player?
    if pygame.sprite.collide_rect(arrow, player):
        reset_arrow()
        player.X -= 20

    #did arrow hit dragon?
    if pygame.sprite.collide_rect(arrow, dragon):
        reset_arrow()
        dragon.X -= 20
        score += 10

    #did dragon eat the player?
    if pygame.sprite.collide_rect(player, dragon):
        game_over = True

    #did the dragon get defeated?
    if dragon.X < -100:
        you_win = True
        game_over = True

    #is the palyer jumping?
    if player_jumping:
        player.Y += jump_vel
        jump_vel += 0.5
        if player.Y > player_start_y:
            player_jumping = False
            player.Y = player_start_y
            jump_vel = 0.0
            jump_before = 0.0

    #draw the background
    screen.blit(bg, (0,0))
    #update sprites
    if not game_over:
        group.update(ticks, 30)

    #draw sprites
    group.draw(screen)

    print_text(font, 350, 560, "Press SPACE to jump!")
    print_text(font, 350, 500, "Score: " + str(score))
    if game_over:
        print_text(font, 360, 100, "G A M E O V E R")
        if you_win:
            print_text(font, 330, 130, "YOU BEAT THE DRAGON!")
        else:
            print_text(font, 330, 130, "THE DRAGON GOT YOU!")

    pygame.display.update()
